Screening for the antidiabetic and associated effects of stem bark extract of Pentaclethra macrophylla benth. (Fabaceae)

The antidiabetic study carried out on the stem bark extract of Pentaclethra macrophylla benth was to investigate the claims behind the traditional use of the plant in the treatment of diabetes mellitus. The anti-diabetic effect of the methanol stem bark extract of P. macrophylla was carried out in the normoglycemic and alloxan-induced diabetic rats. Diabetes was induced in the rats by using alloxan monohydrate 150 mg/kg dissolved in normal saline. Also analysis of the liver and kidney bio-markers were carried out to evaluate and ascertain the effects of the extracts on the vital organs. The normoglycemic and hyperglycemic rats were administered orally with different doses (200, 400 and 800 mg/kg) of the methanol extract of the stem bark of the plant, 5 mg/kg of Glibenclamide (positive control) and 0.1 m1 of normal saline (negative control). The Blood Sugar Levels (BSL) were measured using the ACCU-check glucometer. From the results obtained, it showed that the stem bark extract produced a dose-dependent decrease (P < 0.05) in BSLs of both normal and induced rats. At doses of 200 and 400 mg/kg of the extract administered there was a significant (P < 0.05) reduction in BSL of 14 days with values of 20.6 and 31.1% for the diabetic rats, respectively compared to 12.9% of the negative control. The LD₅₀ of the crude methanol extract was found to be greater than 5000 mg/kg; and hence safe at doses less than the value given. Preliminary phytochemical tests carried on the extract reveals the presence of alkaloids, Saponins, triterpenoids, glycosides etc. In diabetic rats, the liver and kidney enzymes levels were significantly elevated that but were further reduced after administration of the extract. These results indicate that stem bark extract of P. macrophylla may have favorable effects in bringing down the severity of diabetes together with hepatoprotectivity.